Just listen to what the Skychord Cloudbuster does to a Juno-6 at around the 1:35 mark in the video above. It detunes the synth in a modulating say Clockwork Orange soundtrack type of way. Add a little of it’s Pre-amp gain and you have a scary vintage sounding distortion unit. So many little boxes of want lately. This one is $375 USD.

“The cloudbuster is a sequentially modulated lo-fi echo machine featuring harmonically dark burned out lightning strike repeats, howling gore ripping feedback, nightmare time based gurgling, and heavenly comatose modulations. At the heart of the cloudbuster is a four stage sequencer that modulates the delay time via a sequencer. This sequencer has a length of 2 or 4 steps.” – skychord.com

@Bnjmn have you tried a monotron delay yet – some serious sonic mayhem can be had with that cheap little box. And if you use Ableton Live, check out AfroDJMac’s Juno Jive FX – http://afrodjmac.spinshop.com/ it’s $3, and has some nice subtle detuning stuff going on in that rack. Combine it with the Chorus fx from the Kunz Corrupt folks, and it’s a nice set of tools. Lastly, Expert Sleepers Warbler can do everything from subtle to totally-out-there detuning.